WO2002047054A1

WO2002047054A1 - Method of forming electrode for flat panel display

Info

Publication number: WO2002047054A1
Application number: PCT/JP2001/010574
Authority: WO
Inventors: Noriyuki Abe; Masaaki Oda
Original assignee: Ulvac Corporation
Priority date: 2000-12-04
Filing date: 2001-12-04
Publication date: 2002-06-13
Also published as: EP1349135B1; JP4677092B2; EP1349135A4; DE60118042T2; DE60118042D1; CN1175312C; EP1349135A1; US20040043691A1; CN1398390A; KR100813446B1; KR20020080393A; US7247341B2; JP2002169486A; TW548316B

Abstract

A method by which an electrode for flat panel displays (FPDs) is formed from an ink-jet ink with an ink-jet printer. The ink-jet ink, which comprises a dispersion having excellent ink properties, is obtained by a process which comprises: a first step in which a metal vapor is contacted with a first-solvent vapor by the gas vaporization method to obtain a dispersion of ultrafine metal particles; a second step in which a second solvent which is a low-molecular polar solvent is added to the dispersion to settle the ultrafine metal particles and the first solvent is removed by extraction; and a third step in which a third solvent is added to the resultant sediment to conduct solvent replacement and obtain a dispersion of ultrafine metal particles, a dispersant being added in the first step and/or the third step. In the ink, the ultrafine metal particles, which have a particle diameter of 100 nm or smaller, are evenly dispersed independently. Using the ink-jet ink, an electrode for an FPD is formed.

Description

Description FLA) Electrode formation method Technical field

The present invention relates to a method for forming an electrode of a flat panel display (hereinafter, also referred to as FPD) using an ink for an ink jet printer, which is composed of an independent dispersion liquid of ultrafine metal particles and ultrafine metal particles containing a dispersant.

'' Background technology

Conventionally, in the fields of colored paints and conductive paints, ultrafine metal particle dispersions have been used.However, using ultrafine metal particle dispersions as ink and forming FPD electrodes using an inkjet recording method Has not been done to date. There are various types of FPD such as a liquid crystal display (LCD), a plasma display panel (hereinafter, also referred to as a PDP), an organic EL display (EL), a field emission display (FED), and the like. The PDP is typically described below.

Although PDPs are attracting attention as large displays for consumer use, there is an urgent need for significant cost reductions by simplifying the manufacturing process for widespread use. First, the manufacturing process will be described using an example of manufacturing a 42-inch high-definition color PDP. The process consists of two types of manufacturing processes, a front plate and a back plate. First, the electrodes on the front panel are called scan electrodes, and two ITO transparent electrodes are formed on a glass plate for each pixel of 1024 pixels. Since a transparent electrode alone has a high resistance, a metal bus electrode is formed on the transparent electrode. The bus electrode has a width of 50 / m and a thickness of 2 / im.In the conventional process, the bus electrode is formed by a screen printing method using a thick Ag It is formed by an electrode pattern forming method using one photolithography method. Next, the electrodes on the back plate are called address electrodes. Three electrodes are formed directly on the glass plate for each pixel of 1024 pixels. It is. The address electrodes have a width of 50 mm and a thickness of 2 m, and are formed by screen printing, sputtering, or one photolithography method, like the scan electrodes. A glass dielectric layer is formed on both the scan electrode and the padless electrode.

The PDP panel is completed by bonding the front panel and the rear panel to each other after the subsequent processes.However, this electrode forming process is the most complicated and requires a lot of man-hours in the process. It is an obstacle.

As a method for producing the above-described ultrafine metal particle dispersion, the ultrafine metal particle or powder is dispersed with a solvent, a resin, a dispersant, or the like by stirring, application of an ultrasonic wave, a ball mill, a sand mill, or the like, and then the ultrafine particle dispersion Is known, and the dispersion obtained by this method is used in the field of paints and the like. In this production method, for example, as a method of obtaining ultrafine particles directly in a liquid phase, a metal is evaporated in a gas atmosphere and in a gas phase in which a vapor of a solvent coexists, and the evaporated metal is converted into uniform ultrafine particles. A gas-evaporation method that obtains a dispersion by condensing and dispersing in a solvent to obtain a dispersion (Japanese Patent No. 2561357), and a method using an insoluble precipitation reaction or a reduction reaction with a reducing agent are used. is there. Among the methods for producing these ultrafine metal particle dispersions, those based on the gas evaporation method can stably produce a dispersion in which ultrafine particles having a particle size of 100 nm or less are uniformly dispersed. By using a smaller amount of dispersion stabilizer or resin component than in the liquid phase method, an ultrafine particle dispersion having a predetermined concentration can be prepared.

As described above, there has been no example of using a metal ultrafine particle dispersion as an ink for an ink jet, because the conventional metal ultrafine particle dispersion has an ink property that can be used as an inkjet ink. (Viscosity, surface tension, etc.) did not exist. The ultrafine metal particles obtained by the conventional gas evaporation method are agglomerated, and are unlikely to be in a stable state even if they are dispersed in a solvent. Therefore, even when such a dispersion of ultrafine metal particles is used as an ink jet ink, there is a problem that aggregates of ultrafine metal particles may clog the ink jet nozzle. Also, when using the metal ultrafine particle independent dispersion liquid in which the ultrafine particles are independently dispersed as an ink for an ink jet, it is necessary to use a suitable solvent that satisfies the ink characteristics. However, there was a problem that it was not easy to respond to selecting an appropriate solvent. In addition, in the prior art gas evaporation method, when the evaporated metal vapor condenses, the coexisting solvent is denatured to produce by-products. In some cases, problems may arise. Further, as will be described later, there is a problem that, depending on the use of the dispersion, an ultrafine particle dispersion dispersed in a low-boiling solvent, water, or an alcohol-based solvent which is difficult to use in the gas evaporation method is required. There is.

According to the conventional PDP manufacturing process, the front panel and the rear panel are manufactured in different processes, respectively, and finally combined to form a panel.

First, the manufacturing process of the front plate will be described. After the glass substrate acceptance inspection, the ITO pattern of the scan electrode is formed by sputtering and photolithography. Since the resistance of the ITO film alone is high, a metal film with a width of 50 m and a thickness of 2 m is formed as a bus electrode on the ITO film. There are two methods: a screen printing method using the material, and a method of pattern-etching a Cr / Cu / Cr laminated sputtered film by a photolithography method. After the formation of the bus electrode, a glass dielectric layer, a black matrix, a sealing layer, and a MgO layer are sequentially formed thereon, and then the assembly is started to be combined with the back plate.

Next, the manufacturing process of the back plate will be described. After the acceptance inspection of the glass substrate, the address electrodes are formed.This method, like the front plate, uses a screen printing method using a thick-film Ag paste or a laminate of Cr / Cu / Cr. There are two methods: pattern etching of the sputtered film by photolithography. After the address electrodes are formed, a glass dielectric layer, stripe barrier ribs, phosphor layer, and seal layer are sequentially formed thereon, and then the assembly process for assembling with the front panel is performed. After evacuating and filling with gas, aging is performed to fill the PDP panel.

In the process of forming the above electrodes, in the screen printing method, defects in the formation position due to screen displacement, occurrence of oven defects due to pattern formation failure due to clogging of the screen, and materials due to paste remaining on the screen There is a problem of loss. One method of photolithography is a vacuum process, which requires pattern etching by photolithography. It requires 6 to 7 processes such as dist coating, pattern light irradiation, development, etching, and resist asshing, and has a problem that the material used is large because the film is formed over the entire surface.

Accordingly, an object of the present invention is to solve the above-mentioned problems of the prior art, and to prepare an ink jet ink comprising an independent dispersion liquid of ultrafine metal particles, which satisfies the ink characteristics for use as an ink for an ink jet. It is another object of the present invention to provide a method of forming an FPD electrode using an ink jet printer. Disclosure of the invention

In order to achieve the above object, the present inventors have proposed a dispersion liquid in which ultrafine metal particles are dispersed independently, that is, agglomeration of ultrafine particles does not occur and fluidity is maintained. We have been conducting research and development on metal ultrafine particle independent dispersions with excellent properties.However, dispersions obtained through specific processes and using specific dispersants have been Can be solved. In addition, the inventors of the present invention have conducted intensive studies on the formation of PDP electrodes, and have found that a multi-head ink jet printer using an ink composed of an independent dispersion liquid of the metal ultrafine particles capable of being fired at a low temperature of about 300 ° C. By using the evening, there is no waste of materials as in the sputtering method, the screen printing method, etc., and there is no need for vacuum batch processing as in the sputtering method, and there is no need to use a screen as in the screen printing method. The present inventors have found that an electrode pattern can be drawn in a short time without generating a defective forming position due to a positional deviation or an open defect due to clogging of a screen, and thus completed the present invention.

The method for forming an electrode of a flat panel display of the present invention uses a specific ink jet ink, and this ink jet ink is composed of an ultrafine metal particle-independent dispersion liquid containing ultrafine metal particles and a dispersant. In the metal ultrafine particle independent dispersion liquid containing a dispersant, the ultrafine particles are individually and uniformly dispersed independently, and the fluidity is maintained.

The particle diameter of the ultrafine metal particles is usually 100 nm or less, preferably 10 nm or less. The viscosity of the metal ultrafine particle independent dispersion is from l to 100 mPas, preferably from 1 to 10 mPas, and the surface tension is from 25 to 8 mN / m, preferably from 30 to 6 O mN Zm, which satisfies the ink properties for use as an ink for ink jet.

The dispersing agent is one or more selected from alkylamine, carboxylic acid amide, and aminocarboxylic acid salt. In particular, alkylamine has a main chain having 4 to 20 carbon atoms, preferably 8 to 18 carbon atoms. And the alkylamine is preferably a primary amine.

The dispersion liquid contains, as a dispersion medium, a nonpolar hydrocarbon having 6 to 20 carbon atoms in the main chain, water, and at least one solvent selected from alcohol solvents having 15 or less carbon atoms. Is preferred.

The ink jet ink used in the present invention comprises a first step of obtaining a metal ultrafine particle dispersion in which metal ultrafine particles are dispersed in a solvent by evaporating the metal in a gas atmosphere and in the presence of vaporization of the first solvent. The second solvent, which is a low molecular weight polar solvent, is added to the dispersion obtained in the first step to precipitate the metal ultrafine particles, and the first solvent is substantially removed by removing the supernatant. It is produced from a second step of removing and a third step of adding a third solvent to the sediment thus obtained to obtain an independent dispersion of ultrafine metal particles. In the first step and the third or third step, a dispersant is added. Further, the method for producing the ink-jet ink used in the present invention includes the steps of: evaporating a metal in a gas atmosphere and in the presence of a vapor of a first solvent; bringing the vapor of the metal into contact with the vapor of the solvent; Then, a first step of obtaining a metal ultrafine particle dispersion in which the metal ultrafine particles are dispersed in the solvent, and adding a second solvent, which is a low molecular weight polar solvent, to the dispersion obtained in the first step, A second step of substantially removing the first solvent by sedimenting the ultrafine metal particles and removing a supernatant thereof, and adding a third solvent to the sediment obtained in this way to separate the ultrafine metal particles. And a third step of obtaining a dispersion. By adding a dispersant in the first step and / or the third step, a metal ultrafine particle dispersion liquid suitable for an ink jet ink can be obtained.

The third solvent may be at least one selected from non-polar hydrocarbons having 6 to 20 carbon atoms in the main chain, water, and alcohol (having a carbon number of 15 or less) solvents. In the case of ink, it is preferable. BEST MODE FOR CARRYING OUT THE INVENTION

An embodiment of the present invention will be described below.

Regarding the ink characteristics required for the ink jet ink, in order to achieve the stability of ink supply, the stability of ink droplet formation and flight, and the high-speed response of the print head, the temperature during normal operation is required. (0 to 50 ° C), its viscosity is 1 to 10 OmPas, preferably 1 to 10 OmPas, and its surface tension is 25 to 8 OmNZm, preferably 30 to 60 OmN / m, and the ink-jet ink used in the present invention satisfies the characteristics.

As described above, the ultrafine metal particles in the present invention can be produced by a gas evaporation method, and according to this method, the particle diameter is 100 nm or less, preferably 10 nm or less. Ultrafine metal particles can be produced. Since such metal ultrafine particles are used as raw materials and solvent replacement is performed to make them suitable for ink jet inks, a dispersant is added to increase the dispersion stability of these ultrafine particles. As a result, a dispersion liquid suitable for an ink jet ink, in which the ultrafine metal particles are individually and uniformly dispersed, and which maintains a fluid state, can be obtained.

According to the present invention, when an intended metal ultrafine particle dispersion is produced using ultrafine metal particles obtained by an in-gas evaporation method, first, in the first step, in a vacuum chamber and He or the like, The metal is evaporated under an atmosphere in which the pressure of the inert gas is 1 OTorr or less, and when the vapor of the evaporated metal is cooled and collected, one or more types of the first solvent are contained in the vacuum chamber. Vapor is introduced and the surface of the metal is brought into contact with the first solvent vapor at the stage of grain growth to obtain a dispersion in which the obtained primary particles are independently and uniformly colloidally dispersed in the first solvent, In the next second step, the first solvent is removed. The reason why the first solvent is removed is to remove by-products generated by denaturation of the coexisting first solvent when the metal vapor evaporated in the first step is condensed. This is to produce an ultrafine particle independent dispersion dispersed in a low-boiling solvent, water, or an alcohol solvent that is difficult to use in the first step.

According to the present invention, in the second step, the second solvent that is a low molecular weight polar solvent is added to the dispersion obtained in the first step to precipitate ultrafine metal particles contained in the dispersion, The supernatant is removed by a static decantation method or the like to remove the first solvent used in the first step. This second step is repeated a plurality of times to substantially remove the first solvent. Then, in the third step, a new third solvent is added to the sediment obtained in the second step, and the solvent is replaced to obtain a desired ultrafine metal particle dispersion. Thereby, a metal ultrafine particle independent dispersion in which metal ultrafine particles having a particle size of 100 nm or less are dispersed in an independent state is obtained.

According to the present invention, a dispersant can be added in the first step and / or the third step as needed. When added in the third step, a dispersant that does not dissolve in the solvent used in the first step can be used.

The dispersant that can be used in the present invention is not particularly limited, and one or more selected from alkylamines, carboxamides, and aminocarboxylates are used. In particular, as the alkylamine, an alkylamine having a main skeleton of 4 to 20 carbon atoms is preferable, and an alkylamine having a main skeleton of 8 to 18 carbon atoms is more preferable in terms of stability and handling properties. If the number of carbon atoms in the main chain of the alkylamine is less than 4, the basicity of the amine is too strong, which tends to corrode the metal ultrafine particles, and ultimately dissolves the ultrafine particles. Further, if the number of carbon atoms in the main chain of alkylamine is longer than 20, when the concentration of the ultrafine metal particle dispersion is increased, the viscosity of the dispersion is increased and the handling property is slightly deteriorated. There is. Alkylamines of all classes work effectively as dispersants, but primary alkylamines are preferably used in terms of stability and handling.

Specific examples of alkylamines that can be used in the present invention include, for example, butylamine, octylamine, dodecylamine, hexadodecylamine, octadecylamine, cocoamine, evening lauamine, hydrogenated taroamine, oleylamine, laurylamine, and stearylamine. Primary amines such as amines, secondary amines such as dicocoamine, dihydrotallowamine, and distearylamine, and dodecyldimethylamine, didodecylmonomethylamine, tetradecyldimethylamine Tertiary such as octadecyldimethylamine, cocodimethylamine, doden, and trioctylamine Examples of amines include diamines such as naphthylenediamine, stearylpropylenediamine, octamethylenediamine, and nonandiamine. Specific examples of carboxylic acid amide diaminocarboxylates include, for example, stearine. Acid amide, palmitic amide, lauryl laurate, oleic amide, diethanolamide oleic, lauryl oleic, stearanilide, oleylaminoethyldaricin, and the like. One or more of these alkylamines and carboxylic acid amido diamino carboxylate salts can be used, thereby acting as a stable dispersant.

According to the present invention, the content of alkylamine is approximately based on the weight of the ultrafine metal particles.

0. -10% by weight, preferably 0.2-7% by weight. When the content is less than 0.1% by weight, the ultrafine metal particles do not disperse in an independent state, and agglomerates are generated, resulting in poor dispersion stability. If it exceeds, there is a problem that the viscosity of the obtained dispersion becomes high and a gel-like substance is finally formed.

As an application of the ultrafine metal particle dispersion described above, electrode formation of FPD can be considered. In the present invention, an FPD electrode is formed by using this dispersion as an ink composition, especially as an ink for ink jet in a low-priced, high-performance and remarkably popular ink jet printer as a peripheral device of a personal computer recently. be able to. The physical properties such as viscosity and surface tension required as the ink properties of the ink jet ink are as described above. Also, when the solvent selection condition is determined by the difference in usage, such as selecting a polar solvent such as water or alcohol, or a non-polar hydrocarbon solvent according to the properties of the substrate such as a glass substrate or plastic substrate to be printed. There is.

For example, the first solvent is a solvent for generating ultrafine metal particles used in the gas evaporation method, and has a relatively high boiling point so that it can be easily liquefied when cooling and collecting the ultrafine metal particles. is there. Examples of the first solvent include alcohols having 5 or more carbon atoms, for example, solvents containing one or more of terbineol, citroneol, geraniol, and phenethyl alcohol, or organic esters such as benzyl acetate, Ethyl stearate, methyl oleate, ethyl phenylacetate, glyceride, etc. Any solvent containing at least one kind may be used, and can be selected as appropriate depending on the constituent elements of the ultrafine metal particles used or the use of the dispersion.

The second solvent may be any as long as it can precipitate ultrafine metal particles contained in the dispersion obtained in the first step and extract and separate the first solvent to remove it. Solvent Aceton and the like.

As the third solvent, a liquid solvent at room temperature, such as a nonpolar hydrocarbon having 6 to 20 carbon atoms in the main chain, water, or an alcohol having 15 or less carbon atoms, is selected and used. Can be. In the case of non-polar hydrocarbons, if the number of carbon atoms is less than 6, drying is too fast and there is a problem in the handling of the dispersion, and if the number of carbon atoms exceeds 20, the viscosity of the dispersion increases and calcination occurs. There is a problem that carbon is apt to remain in the use which is performed. In the case of alcohol, if the number of carbons exceeds 15, there is a problem that the viscosity of the dispersion increases and carbon is apt to remain in the case of firing.

Examples of the third solvent include long-chain alkanes such as hexane, heptane, octane, decane, pendecane, dodecane, tridecane, and trimethylpentane; Aromatic hydrocarbons such as benzene, toluene, xylene, trimethylbenzene and dodecylbenzene, and alcohols such as hexanol, heptanol, octanol, decanol, cyclohexanol and terpineol can be used. These solvents may be used alone or in the form of a mixed solvent. For example, it may be a mineral spirit that is a mixture of long-chain alkanes.

In the case of the third solvent, a solvent different from the one used in the first step (even if it is the same, but the purity is different) must be used, but the present invention is suitable for such a case. It is.

The constituent elements of the metal ultrafine particles used in the present invention are not particularly limited as long as they are highly conductive metals, and may be appropriately selected according to the purpose. For example, at least one metal selected from gold, silver, copper, palladium, and many other conductive metals, or an alloy of these metals. Among them, silver and copper are preferable because of their high conductivity. In ultrafine metal particles composed of any of these elements, one or more of the above-mentioned alkylamines, carboxamides, and aminocarboxylates may be used. Acts as a dispersant, and the expected dispersion liquid of ultrafine metal particles is obtained.

In the present invention, the concentration of ultrafine metal particles in the ink jet ink used for forming the FPD electrode is 10% by weight to 70% by weight, preferably 10% by weight to 50% by weight. If it is less than 10% by weight, the ink characteristics such as viscosity and surface tension are sufficiently satisfied, but the electric resistance after firing is not a sufficient value for a conductive circuit, and if it exceeds 70% by weight, the viscosity and surface tension are exceeded. Cannot be used as an ink jet for forming FPD electrodes.

Hereinafter, the present invention will be described based on examples. These examples are merely illustrative and do not limit the invention in any way.

(Example 1)

When ultrafine particles of Ag are produced by a gas evaporation method in which silver (Ag) is evaporated under a helium gas pressure of 0.5 Torr, α-terbineol is added to the ultrafine particles of Ag during the production process. 20: 1 (volume ratio) vapor with octylamine, cooled, collected and recovered, and the average particle diameter of 0.08 dispersed independently in α-terbineol solvent. An Ag ultrafine particle independent dispersion liquid containing 25% by weight of Ag ultrafine particles was prepared. Five volumes of acetone were added to one volume of the dispersion, followed by stirring. Ultrafine particles in the dispersion liquid settled out due to the action of polar acetone. After standing for 2 hours, the supernatant was removed, the same amount of acetone as the first was added again, and the mixture was stirred. After standing for 2 hours, the supernatant was removed. To this sediment, dodecane, a non-polar hydrocarbon, was newly added and stirred. The precipitated ultrafine Ag particles had a particle size of about 8 nm, confirming that the particles were dispersed in dodecane in a completely independent state. This dispersion was very stable, and no sedimentation was observed even after one month at room temperature. The Ag content in this dispersion was 23% by weight, the dispersion viscosity was 8 mPa · s, and the surface tension was 35 mNZm.

Similarly, when ultrafine Cu particles are generated by the in-gas evaporation method of evaporating copper (Cu) under the condition of a helium gas pressure of 0.5 Torr, Cu ultrafine particles in the generation process are converted to ultrafine Cu particles. The average particle size of α-terbineol and octylamine in contact with a 20: 1 (volume ratio) vapor, collected by cooling and collected, and dispersed independently in α-terbineol solvent 0 More than 0.7% Cu ultrafine particles containing 27% by weight A fine particle independent dispersion was prepared. Five volumes of acetone were added to one volume of this dispersion, followed by stirring. Ultrafine particles in the dispersion liquid settled out due to the action of polar acetone. After standing for 2 hours, the supernatant was removed, the same amount of acetone as the first was added again, and the mixture was stirred. After standing for 2 hours, the supernatant was removed. To this sediment, dodecane, a non-polar hydrocarbon, was newly added and stirred. The precipitated ultrafine particles of Cu had a particle size of about 7 nm, confirming that the particles were dispersed in dodecane in a completely independent state. This dispersion was very stable, and no sedimentation was observed even after one month at room temperature. The content of Cu in the dispersion was 25% by weight, the viscosity of the dispersion was 9 mPa * s, and the surface tension was 37 mNZm.

A commercially available piezo method was used in which a Cu ultrafine particle independent dispersion was added to the obtained Ag ultrafine particle independent dispersion so that the proportion of Cu in the metal component became 10% by weight as an ink. Using an inkjet printer with a single nozzle, a thin line with a width of 50 m, a coating thickness of 60 zm and a length of 100 mm was drawn on a borosilicate glass substrate. After drawing, baking was performed at 300 ° C for 30 minutes using an electric furnace. As a result, manufacturing an electrode wiring having a width 50 m, thickness of 2. 5 m, its specific resistance value was ^{9. 0 X 10- 6 Ω · cm} . In addition, as a result of a tape test, the electrode wiring did not peel off from the substrate even at a peeling strength of 4.5 kgf / mm ² , and exhibited high adhesion. Next, for a high-definition 16: 9 screen PDP 42 type panel, using a metal ultrafine particle ink as a material, a large XY table with an absolute position accuracy of ± 10 m and a 512 x 510 m pitch interval were used. A scan electrode on the front panel is formed using an ink jet printer equipped with multiple multi-nozzles, and a similar table using an ink jet printer equipped with 512 multi-nozzles with a 900 m pitch interval. The electrode forming process and the panel manufacturing process for forming the address electrodes on the back plate and then forming the PDP panel will be described below.

The 42 type with a screen ratio of 16: 9 has a diagonal length of 1060 mm, the number of pixels is 1024 on both the front and back panels, 1024 x 2 scan electrodes on the front panel, and address electrodes on the rear panel. It consists of 1024 X 3 (RGB) books. The electrode pitch is 510 m for the scan electrode and 900; m for the padless electrode. The electrode width is 50 m and the thickness is 2 m. 5 to 6 pL of ink at a frequency of 14.4 KHz from each nozzle Is controlled so that the ink is discharged. As the ink, an ink in which the Cu ultrafine particle independent dispersion was added to the Ag ultrafine particle independent dispersion so that the ratio of Cu in the metal component was 10% by weight was used.

First, in order to form the bus electrode for the scan electrode, the ITO electrode has already been formed in the conventional process. The diagonal length is 1060 mm and the horizontal-to-vertical ratio is 16: 9. The gate glass substrate was conveyed to a predetermined position on an XY table of a drawing apparatus by a mouth pot, vacuum-adsorbed on a table, and fixed. After accurate positioning of the glass substrate with reference to the positioning markers pre-printed on the four corners of the glass substrate, spaces for forming lead electrodes are provided on both sides of the glass substrate end face.

Drawing was performed in the longitudinal direction of the glass substrate, leaving 15 mm. When the ink was ejected from the nozzle, it spread in a circle of about 50 m on the substrate and dried instantaneously. In order to obtain a film thickness of 2 Xm after firing using this concentration of ink, the circle drawn by each ejection should be overlapped by 2Z3 in the head scanning direction (X-axis direction). That is, the scanning speed of the head was controlled at a speed of (50 mm?,) / {! / 14400) mZ second = 239.9 mm / second. Scan in the X-axis direction to finish the drawing of 5 12 lines, move 200 m in the Y-axis direction, and similarly scan in the X-axis direction to draw 5 12 lines, 5 12 X 2 lines 51 2 The drawing of the paired electrodes of the pixels has been completed. After that, it was moved about 26 lmm in the Y-axis direction, and a 512-pixel pair electrode was similarly drawn. It took about 15 seconds to draw two 1024 X scan electrodes on the front panel. Finally, it moved to both end faces, adjusted the combination of ink ejection from each of the 512 nozzles, and formed the extraction electrode in about 5 seconds. The process of loading the glass substrate into the drawing device, vacuum suction, positioning, drawing the electrodes, drawing the drawn electrodes, and unloading was completed in about 60 seconds. This was one thousandth of the Spaghetti method. From the change in the weight of the cartridge, it was found that the amount of ink used to form the bus electrodes on the front panel was 1.84 g in terms of metal weight. This was about one-fifth of the weight of material used in the sputtering method. In addition, it was confirmed that there were no defective spots in the drawing lines due to sufficient maintenance of the drawing device.

A dielectric glass with a thickness of about 40 m is applied to the entire surface from the top of the dry drawing electrode by a screen printer, and placed in a belt furnace in an air atmosphere, and the keeping time at 600 ° C is 3 hours. The firing was performed with the moving speed set to be 0 minutes.

An address electrode on the back plate was formed directly on the glass substrate at a pitch of 900 m in the same manner as the scan electrode. The drawing of 512 lines was repeated six times, and the formation of 102 4 X 3 address electrodes was completed in about 13 seconds. In the process of forming the electrodes on the back plate, the process from loading to unloading is completed in about 60 seconds, as with the front plate, and the time required for the process can be reduced to one thousandth of that required by the sputtering method. Was.

From the change in weight of the force cartridge, it was found that the amount of ink used for forming the back electrode on the back plate was 1.62 g in terms of metal weight. No defective part was found in the drawing line. Dielectric glass was applied on the obtained address electrodes in the same manner as the scan electrodes, and was baked in a belt furnace.

Next, the front plate and the back plate on which the electrodes were formed as described above were returned to the normal manufacturing process, the two were sealed, evacuated, gas-sealed, and then subjected to aging treatment to form a PDP panel. Assembled. The panel was subjected to a continuous lighting test for 1000 hours, and it was confirmed that the electrodes had sufficient durability. This panel showed no difference in image even when compared to the panel manufactured by the method of the prior art. Industrial applicability

According to the present invention, an FPD electrode is formed by an ink jet printing using an ink jet ink composed of a metal ultrafine particle independent dispersion liquid containing a metal ultrafine particle and a dispersant, so that there is no waste of materials used. Since the manufacturing process can be shortened, the manufacturing cost can be reduced.

Claims

The scope of the claims

1. An electrode forming method for a flat panel display, comprising forming an electrode for a flat panel display using an ink jet ink composed of an independent dispersion liquid of ultrafine metal particles and ultrafine metal particles.

2. a first step of obtaining, as the inkjet ink, a metal ultrafine particle dispersion in which metal ultrafine particles are dispersed in a solvent by evaporating the metal in a gas atmosphere and in the presence of vapor of a first solvent; The second solvent, which is a low molecular weight polar solvent, is added to the dispersion obtained in the first step to precipitate the metal ultrafine particles, and the supernatant is removed to substantially remove the first solvent. A metal ultra-fine particle including a metal ultra-fine particle and a dispersant, which is produced from the second step and the third step of adding a third solvent to the sediment thus obtained to obtain an independent dispersion of ultra-fine metal particles, The method for forming an electrode of a flat panel display according to claim 1, wherein an independent dispersion liquid of fine particles is used.

3. The method for forming an electrode of a flat panel display according to claim 2, wherein a dispersant is added in the first step, the third step, or both the first step and the third step.

4. The metal ultrafine particles have a particle diameter of 100 nm or less, and the viscosity of the metal ultrafine particle independent dispersion is:! The method for forming an electrode of a flat panel display according to claim 1, wherein the surface tension is 25 to 80 mNZm.

5. The ultrafine metal particles have a particle size of 100 nm or less, the viscosity of the metal ultrafine particle independent dispersion is 1 to 10 OmPas, and the surface tension is 25 to 80 mNZm. 3. The method for forming an electrode of a flat panel display according to claim 2, wherein:

6. The method for forming an electrode of a flat panel display according to claim 1, wherein the dispersant is one or more selected from alkylamine, carboxylic acid amide, and aminocarboxylate.

7. The method for forming an electrode of a flat panel display according to claim 2, wherein the dispersant is one or more selected from an alkylamine, a carboxamide, and an aminocarboxylate.

8. The method for forming an electrode of a flat panel display according to claim 4, wherein the dispersant is one or more selected from alkylamine, carboxylic amide, and aminocarboxylate.

9. The electrode forming method for a flat panel display according to claim 6, wherein the carbon number of the main chain of the alkylamine is 4 to 20.

10. The method for forming an electrode of a flat panel display according to claim 7, wherein the main chain of the alkylamine has 4 to 20 carbon atoms.

11. The method for forming an electrode of a flat panel display according to claim 8, wherein the main chain of the alkylamine has 4 to 20 carbon atoms.

12. The method for forming an electrode of a flat panel display according to claim 6, wherein the alkylamine is a primary alkylamine.

13. The method for forming an electrode of a flat panel display according to claim 7, wherein the alkylamine is a primary alkylamine.

14. The method for forming an electrode of a flat panel display according to claim 8, wherein the alkylamine is a primary alkylamine.

15. The dispersion comprises, as a dispersion medium, at least one solvent selected from non-polar hydrocarbons having 6 to 20 carbon atoms in the main chain, water, and alcohol solvents having 15 or less carbon atoms. 2. The method for forming an electrode of a flat panel display according to claim 1, comprising:

16. The dispersion comprises, as a dispersion medium, at least one solvent selected from non-polar hydrocarbons having 6 to 20 carbon atoms in the main chain, water, and alcohol solvents having 15 or less carbon atoms. 3. The method for forming an electrode of a flat panel display according to claim 2, comprising:

17. The dispersion liquid comprises, as a dispersion medium, at least one solvent selected from a nonpolar hydrocarbon having 6 to 20 carbon atoms in the main chain, water, and an alcohol solvent having 15 or less carbon atoms. 5. The method for forming an electrode of a flat panel display according to claim 4, comprising:

18. The dispersion liquid comprises, as a dispersion medium, at least one solvent selected from non-polar hydrocarbons having 6 to 20 carbon atoms in the main chain, water, and alcohol solvents having 15 or less carbon atoms. 7. The method for forming an electrode of a flat panel display according to claim 6, comprising an agent.

19. The dispersion comprises, as a dispersion medium, at least one solvent selected from non-polar hydrocarbons having 6 to 20 carbon atoms in the main chain, water, and an alcohol solvent having 15 or less carbon atoms. 8. The method for forming an electrode of a flat panel display according to claim 7, comprising:

20. The dispersion liquid, as a dispersion medium, at least one solvent selected from a nonpolar hydrocarbon having 6 to 20 carbon atoms in the main chain, water, and an alcohol solvent having 15 or less carbon atoms. 10. The method for forming an electrode of a flat panel display according to claim 9, comprising:

21. The dispersion liquid comprises, as a dispersion medium, at least one solvent selected from a nonpolar hydrocarbon having 6 to 20 carbon atoms in the main chain, water, and an alcohol solvent having 15 or less carbon atoms. 13. The method for forming an electrode of a flat panel display according to claim 12, wherein the method comprises: